http://www.w3.org/Bugs/Public/show_bug.cgi?id=4348
Summary: Remove single-ID-attribute rule
Product: XML Schema
Version: 1.1 only
Platform: Macintosh
OS/Version: All
Status: NEW
Keywords: unclassified
Severity: normal
Priority: P2
Component: Structures: XSD Part 1
AssignedTo: cmsmcq@w3.org
ReportedBy: cmsmcq@w3.org
QAContact: www-xml-schema-comments@w3.org
Like XML Schema 1.0, and like XML DTDs and SGML DTDs before it, XML Schema 1.1
forbids schema authors to declare more than one attribute of an element as
having type ID.
This restriction never made much sense, and it's currently getting in the way
of users as various as the HTML Working Group and the Web Services Policy
Working Group, as well as anyone else with an existing XML vocabulary with
defined ID attributes who would like to make it possible for authors to use
xml:id in addition to, or instead of, their existing ID attributes.
As we have done in other cases where we have decided not to enforce
restrictions
imposed by our predecessor languages, we should add a note mentioning that
declarations with multiple ID attributes can't be translated into DTD
notation without loss.
But we should then drop the current restriction and allow multiple
ID attributes on a given element.